Microwave ablation instrument with interchangeable antenna probe

ABSTRACT

A surgical ablation system features a source of ablation energy, a handle adapted to operably couple to the source of ablation energy, and an ablation probe adapted to operably couple to the handle. The handle includes a housing having a proximal end and a distal end, a hub included within the housing having a plenum defined therein, and a proximal feedline in fluid communication at a proximal end thereof with the plenum and joined at a distal end thereof to a first coupling member. The ablation probe includes a probe hypotube shaft having a proximal end and a distal end, a second coupling member disposed at a proximal end of the probe hypotube shaft adapted to operably couple with the first coupling member, a distal tip adapted to penetrate tissue. Ablation energy is deliverable by the ablation probe when the source of ablation energy is operably coupled to the handle and the handle is operably coupled to the ablation probe.

BACKGROUND

1. Technical Field

The present disclosure relates to systems and methods for providing energy to biologic tissue and, more particularly, to an electrosurgical instrument adapted to perform tissue ablation having an interchangeable antenna probe.

2. Background of Related Art

Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency energy from the electrosurgical generator to the tissue and a return electrode carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated. A patient return electrode is placed remotely from the active electrode to carry the current back to the generator. In tissue ablation electrosurgery, the radio frequency energy may be delivered to targeted tissue by an antenna or probe.

There are several types of microwave antenna assemblies in use, e.g., monopole, dipole and helical, which may be used in tissue ablation applications. In monopole and dipole antenna assemblies, microwave energy generally radiates perpendicularly away from the axis of the conductor. Monopole antenna assemblies typically include a single, elongated conductor. A typical dipole antenna assembly includes two elongated conductors, which are linearly-aligned and positioned end-to-end relative to one another with an electrical insulator placed therebetween. Helical antenna assemblies include a helically-shaped conductor connected to a ground plane. Helical antenna assemblies can operate in a number of modes including normal mode (broadside), in which the field radiated by the helix is maximum in a perpendicular plane to the helix axis, and axial mode (end fire), in which maximum radiation is along the helix axis. The tuning of a helical antenna assembly may be determined, at least in part, by the physical characteristics of the helical antenna element, e.g., the helix diameter, the pitch or distance between coils of the helix, and the position of the helix in relation to the probe assembly to which it is mounted.

The typical microwave antenna has a long, thin inner conductor that extends along the longitudinal axis of the probe and is surrounded by a dielectric material and is further surrounded by an outer conductor around the dielectric material such that the outer conductor also extends along the axis of the probe. In another variation of the probe that provides for effective outward radiation of energy or heating, a portion or portions of the outer conductor can be selectively removed. This type of construction is typically referred to as a “leaky waveguide” or “leaky coaxial” antenna. Another variation on the microwave probe involves having the tip formed in a uniform spiral pattern, such as a helix, to provide the necessary configuration for effective radiation. This variation can be used to direct energy in a particular direction, e.g., perpendicular to the axis, in a forward direction (i.e., towards the distal end of the antenna), or combinations thereof. In the case of tissue ablation, a high radio frequency electrical current in the range of about 500 MHz to about 10 GHz is applied to a targeted tissue site to create an ablation volume, which may have a particular size and shape. Ablation volume is correlated to antenna design, antenna tuning, antenna impedance and tissue impedance.

Certain surgical procedures require multiple ablation probe placements. Needle probes that are frequently used in such procedures may become dull and bent, and consequently may become more difficult to place when reused. To address this concern, surgeons may utilize multiple probes during a surgical procedure. This approach may have drawbacks in that when multiple probes are place, the handles and cables associated with the multiple probes can be cumbersome to coordinate and manipulate at a surgical site. This, in turn, may lead to increased operative times and suboptimal surgical outcomes.

SUMMARY

The present disclosure is directed to a microwave ablation instrument having a handle portion and an interchangeable antenna probe. The replaceable probe may be reusable or disposable. The probe is adapted to operably connect to the handle using a connector configured to provide electrical and fluidic coupling between the handle and probe. The probe includes a monopole or dipole antenna assembly configured to deliver ablation energy to tissue. The handle is adapted to operable couple to a source of ablation energy, e.g., a generator. The handle may additionally or alternatively be configured to couple to a source of coolant. In use, a surgeon may insert one or more of the interchangeable probes into preselected regions of targeted tissue. The surgeon may then attach the handle to a first probe, activate the generator to deliver ablation energy to the first region of tissue, then move the handle to a second probe, and so forth, to deliver ablation energy to each pre-positioned probe in turn. In this manner, a single handle may be used to treat multiple regions of tissue without requiring repeated re-insertion of a single probe. In addition, use of a single handle with multiple interchangeable probes, rather than a multiple prior art handles each with a fixed probe, may significantly reduce the number of cables and clutter at the operative site, which benefits both surgeon and patient by streamlining procedures and improving operative outcomes.

The probe many include a monopole antenna, a dipole antenna, and variations thereof, such as without limitation, a wet-tip monopole antenna or a choked wet-tip dipole antenna.

A surgical ablation system in accordance with an embodiment of the present disclosure includes a source of ablation energy, a handle adapted to operably couple to the source of ablation energy, and an ablation probe adapted to operably couple to the handle. The handle includes a housing having a proximal end and a distal end, a hub included within the housing having a plenum defined therein, and a proximal feedline in fluid communication at a proximal end thereof with the plenum and joined at a distal end thereof to a first coupling member. The ablation probe includes a probe hypotube shaft having a proximal end and a distal end, a second coupling member disposed at a proximal end of the probe hypotube shaft adapted to operably couple with the first coupling member, a distal tip adapted to penetrate tissue. Ablation energy is deliverable by the ablation probe when the source of ablation energy is operably coupled to the handle and the handle is operably coupled to the ablation probe.

A disposable ablation probe in accordance with an embodiment of the present disclosure includes a probe hypotube shaft having a proximal end and a distal end, a probe inner conductor disposed along a longitudinal axis of the probe hypotube shaft, a probe insulator coaxially-disposed about probe inner conductor, a probe outer conductor coaxially disposed about probe insulator, and a probe coolant tube concentrically-disposed between the probe hypotube and the probe outer conductor to form a probe inflow conduit and a probe outflow conduit. A cooling chamber is defined within the distal end of the probe hypotube shaft and is in fluid communication with at least one of the probe inflow conduit or the probe outflow conduit. A coupling member is disposed at a proximal end of the probe hypotube shaft and is adapted to operably couple the probe to a handle. At a distal end of the hypotube shaft is a tip adapted to penetrate tissue.

An embodiment of a surgical instrument handle for use with a disposable ablation probe in accordance with the present disclosure includes a housing having a proximal end and a distal end, a hub included within the housing having a plenum defined therein, and a proximal feedline in fluid communication at a proximal end thereof with the plenum and joined at a distal end thereof to a first coupling member. The proximal feedline includes a feedline hypotube shaft having a proximal end and a distal end, a feedline inner conductor disposed along a longitudinal axis of the feedline, a feedline insulator coaxially-disposed about feedline inner conductor, a feedline outer conductor coaxially disposed about feedline insulator, and a feedline coolant tube concentrically-disposed between feedline hypotube and the feedline outer conductor to form a feedline inflow conduit and a feedline outflow conduit.

Also disclosed is an ablation system having a source of ablation energy operatively coupled to an ablation probe as described herein. The disclosed system may further include at least one of a source of coolant or a source of pressure operatively coupled to an ablation probe as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a schematic diagram of an embodiment of an ablation system that includes a handle and a removable probe in accordance with the present disclosure;

FIG. 2 shows a side, cutaway view of an ablation instrument having a handle and a removable probe in accordance with the present disclosure;

FIG. 3 shows a schematic view of the relationship between components of an ablation instrument having a removable probe in accordance with the present disclosure;

FIG. 4 shows an enlarged, cutaway view of a hub portion of an ablation instrument having a removable probe in accordance with the present disclosure;

FIG. 5 shows an enlarged, cutaway view of a connector portion of an ablation instrument having a removable probe in accordance with the present disclosure;

FIG. 6 shows a section view of a feedline of an ablation instrument having a removable probe in accordance with the present disclosure;

FIG. 7 shows an enlarged, cutaway view of a tip portion of an ablation instrument having a removable probe in accordance with the present disclosure;

FIG. 8 shows a side, cutaway view of another embodiment of a removable antenna assembly in accordance with the present disclosure;

FIG. 9 shows a section view of the FIG. 8 removable antenna assembly;

FIG. 10 shows a detailed side, cutaway view of a male connector of the FIG. 8 removable antenna assembly;

FIG. 11 shows a detailed side, cutaway view of a female connector of the FIG. 8 removable antenna assembly; and

FIGS. 12A-12F show an ablation procedure performed utilizing an ablation instrument in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions and repetitive matter are not described in detail to avoid obscuring the present disclosure in unnecessary or redundant detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.

In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, shall refer to the end of the instrument that is closer to the user, while the term “distal” shall refer to the end that is farther from the user. In addition, as used herein, terms referencing orientation, e.g., “top”, “bottom”, “up”, “down”, “left”, “right”, “clockwise”, “counterclockwise”, and the like, are used for illustrative purposes with reference to the figures and features shown therein. It is to be understood that embodiments in accordance with the present disclosure may be practiced in any orientation without limitation. In this description, as well as in the drawings, like-referenced numbers represent elements which may perform the same, similar, or equivalent functions.

References to connector gender presented herein are for illustrative purposes only, and embodiments are envisioned wherein the various components described can be any of male, female, hermaphroditic, or sexless gender. Likewise, references to circular and coaxial connectors are illustrative in nature, and other connector types, shapes and configurations are contemplated within the scope of the present disclosure.

Electromagnetic energy is generally classified by increasing energy or decreasing wavelength into radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma-rays. As it is used in this description, “microwave” generally refers to electromagnetic waves in the frequency range of 300 megahertz (MHz) (3×10⁸ cycles/second) to 300 gigahertz (GHz) (3×10¹¹ cycles/second). As it is used in this description, “ablation procedure” generally refers to any ablation procedure, such as microwave ablation, radio frequency (RF) ablation, or microwave ablation assisted resection. As it is used in this description, “transmission line” generally refers to any transmission medium that can be used for the propagation of signals from one point to another.

Various embodiments of the present disclosure provide electrosurgical devices operably associated with directional reflector assemblies for treating tissue and methods of directing electromagnetic radiation to a target volume of tissue. Embodiments may be implemented using electromagnetic radiation at microwave frequencies, or, at other frequencies. An electrosurgical system having an aperture assembly that includes an energy applicator operably associated with a directional reflector assembly, according to various embodiments, is configured to operate between about 300 MHz and about 10 GHz with a directional radiation pattern.

Various embodiments of the presently disclosed electrosurgical devices, directional reflector assemblies, thereto and electrosurgical system including the same are suitable for microwave ablation and for use to pre-coagulate tissue for microwave ablation assisted surgical resection. Although various methods described hereinbelow are targeted toward microwave ablation and the destruction and/or resection of targeted tissue, it is to be understood that methods for directing electromagnetic radiation may be used with other therapies in which the target tissue is partially destroyed, damaged, or dissected, such as, for example, to prevent the conduction of electrical impulses within heart tissue. In addition, the teachings of the present disclosure may apply to a dipole, monopole, helical, or other suitable type of microwave antenna.

FIG. 1 shows an ablation system 10 in accordance with an embodiment of the present disclosure. The ablation system 10 includes an ablation instrument 12 that is operably connected by a cable 15 to connector 16, which further operably connects instrument 12 to a generator assembly 14. Generator assembly 14 may be a source of ablation energy, e.g., microwave or RF energy in the range of about 915 MHz to about 10.0 GHz. Instrument 12 is adapted for use in various surgical procedures and generally includes a handle assembly 30 configured to operably engage with an antenna probe 20. A proximal end 23 of probe 20 electromechanically engages a distal end 31 of handle 30. Cable 15 may additionally or alternatively provide a conduit (not explicitly shown in FIG. 1) configured to provide coolant from a coolant source 18 to ablation instrument 12.

Turning to FIGS. 2, 3, and 4, an embodiment of an ablation instrument in accordance with the present disclosure includes a handle 30 having a housing 32. Housing 32 may be assembled from a two piece (left and right half) clamshell-type assembly that is joined along a common edge by any suitable manner of attachment, e.g., laser welding, chemical welding, adhesive, mechanical fasteners, clips, threaded fasteners and the like. Housing 32 includes a hub 34 that couples a handle feedline 70 with an input cable 60, an inflow tube 40 and an outflow tube 41. Hub 34 includes a plenum 42 that receives spent coolant from a proximal end 46 of feedline outflow conduit 48, and from which spent coolant flows into outflow tube 41. Input cable 60 includes an inner conductor 62 coaxially disposed within an outer conductor 64 having an insulator 63 disposed therebetween.

Proximal feedline 70 includes a number of elements arranged concentrically therein that are adapted to deliver electrosurgical energy and coolant to antenna probe 20 and to remove coolant from antenna probe 20. Proximal feedline 70 is formed from a feedline hypotube 51 that extends distally from a distal end 35 of hub 34 and terminates distally within male luer-style member 24, as shown in FIG. 5. Input cable 60 extends through a proximal wall of hub 34 via sealed port 66 and continues through plenum 42 and a longitudinal axis of feedline hypotube 51 and terminates distally within male luer-style member 24. As seen in FIG. 6, input cable 60 includes feedline inner conductor 62 disposed along a longitudinal axis thereof. A feedline insulator 63 is coaxially disposed about feedline inner conductor 62. A feedline outer conductor 64 is disposed about feedline insulator 63. A feedline coolant tube 50 is concentrically disposed between feedline hypotube 51 and input cable 60 to form a feedline inflow conduit 47 and a feedline outflow conduit 48. A proximal end 46 of feedline outflow conduit 48 is in fluid communication with plenum 42. A distal end 45 of inflow tube 40 is in fluid communication with a proximal end of feedline inflow conduit 47 to provide coolant during use to antenna probe 20. A seal 49 is disposed at a proximal end of feedline coolant tube 50 to direct inflowing fresh coolant distally through feedline inflow conduit 47 and to prevent intermingling of inflowing fresh coolant with spent coolant exiting through feedline outflow conduit 48. A distal end 65 of feedline inner conductor 62 extends beyond a distal end of cable 60 and is adapted to engage an inner conductor connector 86 to facilitate the electrical coupling of feedline inner conductor 62 with a probe inner conductor 82 when antenna probe 20 is joined to handle 30.

Handle 30 includes an actuator 71, which may be a handswitch as shown, or, alternatively, and without limitation, a trigger switch, a pushbutton switch, a slide switch, a lever switch, that is configured to activate generator 14 when actuated by a surgeon. Actuator 71 may be operably coupled to generator 14 by control cable 72 and/or control cable 73. In an embodiment, actuator 71 includes a momentary-contact, single pole single throw (SPST) switch. In an embodiment, actuator 71 may include a snap dome switch. An interlock (not explicitly shown) may be included in handle 30 to inhibit actuation of generator 14 when no antenna probe 20 is coupled to handle 30.

Antenna probe 20 includes a probe hypotube 81 shaft having an internal structure that generally corresponds to that of feedline hypotube 51 and includes features at a proximal end 23 thereof adapted to operatively engage a distal end of feedline hypotube 51. Hypotube 81 includes a probe inner conductor 82 that extends along a longitudinal axis of hypotube 81. A probe insulator 83 is coaxially-disposed about probe inner conductor 81, and a probe outer conductor 84 is coaxially-disposed about insulator 83. A probe coolant tube 80 is concentrically-disposed between probe hypotube 81 and probe outer conductor 84 to form a probe inflow conduit 87 and a probe outflow conduit 88.

An inner conductor connector 86 is operatively fixed to probe inner conductor 82 and is configured to operably engage feedline inner conductor 62 when antenna probe 20 is joined to handle 30. As shown, inner conductor connector 86 is configured as a female connector, however, inner conductor connector 86 may be a male connector, a hermaphroditic connector, or any other suitable form of connector. Probe outer conductor 84 includes an outer conductor connector 85 operatively fixed to a proximal end thereof that is configured to operably engage a proximal end 66 of feedline outer conductor 64 when antenna probe 20 is joined to handle 30.

The conductor connectors may be joined to their respective conductors (e.g., inner conductor connector 86 to probe inner conductor 82, and outer conductor connector 85 to outer conductor 84) by any suitable manner of electromechanical bonding, including without limitation soldering, brazing, welding, crimping, or threaded fastener. An outer conductor insulator (not explicitly shown) may be coaxially disposed about feedline outer conductor 64 and/or probe outer conductor 84.

A proximal end of probe hypotube 81 includes a hypotube flared section 89 that is configured to form a fluid-tight connection around a distal end of feedline hypotube 51. A proximal end of probe coolant tube 80 includes a coolant tube flared section 90 that is configured to form a fluid-tight connection around a distal end of feedline coolant tube 50. In an embodiment, the mating surfaces between feedline hypotube 51 and hypotube flared section 89, and between feedline coolant tube 50 and coolant tube flared section 90 may include seal-enhancing elements (not explicitly shown), including without limitation an o-ring, elastomeric coating, a lubricious coating, or a series of interlocking ridges. In an embodiment, the flared sections, i.e., hypotube flared section 89 and/or coolant tube flared section 90, may be configured to expand upon the insertion of the corresponding mating proximal component, i.e., feedline hypotube 51 and/or feedline coolant tube 50, respectively, which, in turn, provides improved sealing between the joined components.

The handle 30 and antenna probe include coupling elements 24 and 22, respectively, that are adapted to operatively couple handle 30 and probe 20. More particularly, and as seen in FIGS. 5 and 6, handle 30 includes a male luer-style member 24 that is configured to operably engage a female luer-style collar 22. When coupled, an outer mating surface 25 of male luer member 24 engages an inner mating surface 26 of female luer collar 22 to retain antenna probe 20 to handle 30 in a fixed relationship. In an embodiment, male luer member 24 engages an inner mating surface 26 of female luer collar 22 by frictional retention. In other envisioned embodiments within the scope of the present disclosure, male luer member 24 engages female luer collar 22 by any suitable manner of connection, including without limitation, threaded engagement, bayonet mount (e.g., “half-twist” connector), quick disconnect connector (MPT-FTP pair), and the like.

While in the example embodiment the coupling elements 24 and 22 are male and female couplers, respectively, embodiments in accordance with the present disclosure may utilize any combination of cooperative male, female, and hermaphroditic couplers 24 and 22 to effectuate operative coupling of handle 30 and probe 20.

Turning now to FIG. 7, hypotube 81 extends distally and includes a distal tip 21 having a contour configured to facilitate piercing of tissue. As shown, tip 21 includes a generally conical tapered section 99, however, other tip configurations are within the scope of the present disclosure, including without limitation, chisel tip, flat tip, spoon tip, and so forth. A cooling chamber 92 is defined within tip 21 to facilitate the circulation of coolant therein and to control the temperature of probe 20. A distal end 93 of probe coolant tube 80 defines a coolant inflow port 94 through which coolant flows form probe inflow conduit 87 into coolant chamber 92. A distal end 93 of probe coolant tube 80 also defines coolant outflow port 95, that is arranged generally concentrically about coolant inflow port 94, and through which spent coolant flows from coolant chamber 92 proximally into probe outflow conduit 88.

Probe insulator 83 and probe inner conductor 82 extend distally beyond a distal end 93 of coolant tube 80 and/or a distal end 96 of probe outer conductor 84 into cooling chamber 92. A distal end 100 of inner conductor 82 extends distally beyond a distal end 97 of probe insulator 83 into distal radiating section 91. Distal radiating section 91 is electromechanically coupled to a distal end 100 of probe inner conductor by any suitable manner of attachment, including without limitation soldering, welding, brazing, crimping, and the like. A quarter wave balun 98 may be coaxially disposed about outer conductor 98 to form a quarter-wave short-circuiting balun adapted to contain the radiated microwave energy to the region of tip 21.

An ablation probe 20 in accordance with the present disclosure may have a length L that ranges from about 1 cm to about 1 m in length. During a surgical procedure, a surgeon may elect to use one or more ablation probes, in one or more lengths, in order to achieve the desired surgical outcome. The diameter D of an ablation probe in accordance with the present disclosure may have a range of about 0.1 mm to about 10 mm.

In an embodiment, a kit that includes a handle assembly 30 and a plurality of ablation probes 20 may be provided to a surgeon. The quantity, length, and/or diameter of the ablation probes provided in the kit may be based at least in part by a particular surgical procedure for which the kit may be suited. The kit may be provided in sterile packaging to ensure the handle 30 and probes 20 are provided to the surgical site free of biocontaminants.

Another example embodiment according to the present disclosure is illustrated in FIGS. 8-11. An antenna assembly 200 includes a handle-side coupler 240 and an antenna probe 280. A proximal end 284 of probe 280 may be selectively and releasably engageable with the handle assembly 231 or a portion thereof, e.g., coupler 240. Antenna probe 280 may be considered disposable, reusable, and may be referred to by the portmanteau “reposable.” Accordingly, a new or different probe 280 may selectively replace a prior-coupled probe 280 as required.

Hypotube 210 is fixed within a handle 230. Hypotube 230 may be formed from any suitable material capable of delivering fluid and/or capable of conducting electricity, such as without limitation, stainless steel. Hypotube 201 may be operably coupled to a source of electrosurgical energy by a conductor 264. Coupler 240 includes a male connector 224 that is fixed to a distal end 231 of handle 230. Male connector 224 may be a luer-style connector formed from an electrically conductive, rigid material including without limitation, stainless steel. Male connector 224 is electrically coupled to hypotube 201. In one aspect, the combination of conductor 264, hypotube 201, and/or connector 224 are adapted to deliver electrosurgical energy to probe 280, as will be further described in detail below.

Connector 225 includes a proximal base portion 228 having a diameter that is configured to fixably engage hypotube 201 around an outer diameter thereof to form an electrically-conductive and fluid-tight connection therewith. Proximal base portion 228 of connector 224 may extend proximally into handle 230, which may increase the ridigity and junction strength of the overall antenna assembly 200. A flared distal portion 226 of connector 224 having a diameter greater than that of proximal base portion 228 forms an internal plenum volume 227 to accommodate the flow of coolant exiting from antenna probe 280, and includes a distal rim 225 configured to selectively engage a corresponding circumferential saddle 285 defined within a female connector 282 that is fixed at a proximal end 284 of probe 280.

A coolant tube 202 is positioned concentrically within hypotube 201. The inner portion of coolant tube 202 defines an inflow conduit 207 that is adapted to deliver coolant from a coolant source (not explicitly shown in this view), that may be operably coupled to a proximal end of coolant tube 202, to probe assembly 280. An outflow conduit 208 is defined by the coaxial arrangement of coolant tube 202 and hypotube 201, and is in fluid communication with plenum 277 to receive spent coolant exiting from probe 280. Coolant tube 202 may be formed from any suitable material, however it is envisioned coolant tube 202 is formed from conductive material. Coolant tube 202 may be operably coupled to a source of electrosurgical energy by a conductor 262. By this arrangement, coolant tube 202 may be adapted to provide electrosurgical energy to probe 280. Coolant tube 202 extends distally to about a plane defined by a distal rim 225 of connector 224.

Probe 280 includes a number of features designed to facilitate the selective operable engagement with coupler 240. Female coupler 250 includes a female connector 282 that is fixed to a proximal end 284 of probe 280. Female connector 282 may be a luer-style connector formed from an electrically conductive, rigid material including without limitation, stainless steel. Female connector 282 is electrically coupled to probe hypotube 281. Female connector 282 and/or probe hypotube 281 may be formed from any suitable electrically-conductive, high-strength, temperature resistant material, such as without limitation, stainless steel. A distal end of probe hypotube 281 includes a trocar tip 299 that has a generally tapered shape, e.g., conical, to facilitate the penetration thereof, and probe 280 generally, into tissue. A circumferential saddle 285 is defined within female connector 282 and configured to selectively operably engage rim 225 of connector 224 to facilitate the electromechanical coupling of probe 280 to handle 230. Saddle 285 and rim 225 may engage using any suitable manner of engagement, including without limitation a snap fit, interference fit, cooperating threaded engagement, or a bayonet (e.g., “half-twist”) coupling. When coupled, the combination of connector 224 and connector 282 enables the conduction of electrosurgical energy therethrough.

Probe 280 includes a generally tubular antenna element 293 concentrically disposed within probe hypotube 281. A proximal end of antenna element 293 includes a female barrel coupler 290 that is configured to operably engage a distal end 203 of coolant tube 202. A distal end of antenna element 293 may include a flared opening 294, though which coolant exiting from inflow conduit 287 flows into a cooling chamber 291 defined within probe hypotube 281. Barrel coupler 290 may be integrally formed with antenna element 293, by, e.g., forging, cold rolling, or machining, or may be separately fabricated and joined to antenna element 293 by, e.g., welding, brazing, soldering, crimping, and/or by threaded fastening. An o-ring 289 or other form of resilient seal is retained within barrel connector 290 to promote a fluid-tight connection between coolant tube 202 and antenna element 293, and to isolate spent coolant in and around the region of plenum 227 from the inflow conduits 207 and/or 287. Barrel connector 290 may include one or more crimps or serrations 283 configured to retain o-ring 289 in place. When antenna probe 280 is coupled to handle 230, electrosurgical energy is conducted between coolant tube 202, barrel coupler 290, and antenna element 293 to deliver electrosurgical ablation energy to targeted tissue.

One or more spacers 286 may be included within probe hypotube 281 and adapted to center antenna element 293 within hypotube 281. Spacer 286 includes one or more support legs 292 extending radially from a central hub 295. Central hub 295 is configured to retain antenna element 293 centrally within probe hypotube 281 to, e.g., define outflow conduit 288, to prevent short circuits between antenna element 293 and hypotube 281, and to promote secure engagement between barrel coupler 290 and coolant tube 202. Spacer 286 may be formed from any suitable fluid- and temperature-resistant electrically insulative material. A thermosetting polymer, such as without limitation, polyimid, may be advantageously used to form spacer 286.

Turning now to FIGS. 12A-12F, a method of performing an ablation procedure on targeted tissue T is illustrated. A surgeon determines, based on operative requirements, the number, size (e.g., length and diameter), and placement of the ablation probes 20. As shown in FIG. 12A, a plurality of probes 20, 20′, 20″ . . . 20 ^(n) are inserted into targeted tissue T. Naturally, a greater or lesser number of probes 20 may be inserted as required, and the probes 20 may be of differing lengths and diameters as required.

Handle 30 is also operatively coupled to a generator 14 and may, additionally, be operatively coupled to a coolant source 18 as described hereinabove.

After the desired probes are positioned, a surgeon may bring a handle 30 into axial alignment with a first probe with which ablation energy is delivered to tissue T. As seen in FIGS. 12B and 12C, a surgeon aligns the handle 30 with first probe 20 such that male luer member 24 is positioned to engage female luer collar 22, mates the male luer member 24 to the female luer collar 22, and secures male luer member 24 to female luer collar 22 to form an ablation instrument 12 in accordance with the present disclosure. In various embodiments, male luer member 24 may be secured to female luer collar 22 by twisting, threading, or otherwise manipulating the engaging portions thereof accordingly to affectuate engagement.

After engaging the handle 30 to the first probe 20 to form instrument 12, the surgeon may then activate the generator 14 to deliver ablation energy to tissue T as shown in FIG. 12D. The activation of generator 14 may additionally activate the delivery of coolant from coolant source 18 through instrument 12. When the desired ablation energy has been delivered to tissue, the generator 14 (and delivery of coolant, if activated) is deactivated

The surgeon may then de-couple handle 30 from ablation probe 20, and couple handle 30 to a subsequent probe 20′, and ablation energy applied to the second probe 20′. The procedure is repeated as required with each successive ablation probe 20″ . . . 20 ^(n) as illustrated by FIGS. 12E and 12F until each probe 20 et seq. has delivered ablation energy to tissue T.

The described embodiments of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment of the present disclosure. It is to be understood that the steps of a method provided herein may be performed in combination and/or in a different order than presented herein without departing from the scope and spirit of the present disclosure. Further variations of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be made or desirably combined into many other different systems or applications without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law. 

What is claimed is:
 1. An ablation instrument, comprising: a handle assembly including: a handle hypotube having a distal portion; a first coupling member coupled to the distal portion of the handle hypotube; a handle feedline extending longitudinally through the handle hypotube and configured to be coupled to an electrosurgical energy source, the handle feedline including: an outer conductor having a distal portion; and an inner conductor having a distal portion that extends distally from the distal portion of the outer conductor; and a handle coolant tube extending longitudinally between the handle hypotube and the outer conductor of the handle feedline to define an outflow conduit that extends longitudinally between the handle coolant tube and the handle hypotube and an inflow conduit that extends longitudinally between the handle coolant tube and the outer conductor, the handle coolant tube having a distal portion; and an ablation probe configured to detachably couple to the handle assembly, the ablation probe including: a probe hypotube having a proximal portion configured to form a fluid-tight seal with the distal portion of the handle hypotube; a second coupling member coupled to the proximal portion of the probe hypotube and configured to be detachably coupled to the first coupling member of the handle assembly; a probe feedline extending through the probe hypotube and including: an outer conductor having a proximal portion configured to be detachably coupled to the distal portion of the outer conductor of the handle feedline; and an inner conductor having a proximal portion defining an elongated cavity therein, the elongated cavity configured to detachably receive the distal portion of the inner conductor of the handle feedline; and a probe coolant tube extending longitudinally between the probe hypotube and the outer conductor of the probe feedline to define an outflow conduit that extends longitudinally between the probe coolant tube and the probe hypotube, and an inflow conduit that extends longitudinally between the probe coolant tube and the outer conductor of the probe feedline, the probe coolant tube having a proximal portion configured to detachably couple to the distal portion of the handle coolant tube and to selectively form a fluid-tight seal with the distal portion of the handle coolant tube such that, upon coupling of the ablation probe to the handle assembly, the inflow conduit of the probe coolant tube is continuous with the inflow conduit of the handle coolant tube and the outflow conduit of the probe coolant tube is continuous with the outflow conduit of the handle coolant tube.
 2. The ablation instrument in accordance with claim 1, wherein the handle assembly includes a hub having a proximal portion configured to couple to an input cable and a distal portion configured to couple to a proximal portion of the handle hypotube.
 3. The ablation instrument in accordance with claim 2, wherein the hub defines a plenum therein that is in fluid communication with the outflow conduit of the handle coolant tube, the proximal portion of the hub defining an opening in fluid communication with an outflow tube.
 4. The ablation instrument in accordance with claim 3, wherein the handle assembly includes an inflow tube coupled to a proximal portion of the inflow conduit of the handle coolant tube.
 5. The ablation instrument in accordance with claim 2, wherein the handle assembly includes a housing having the hub, the handle feedline, and the handle hypotube disposed therein.
 6. The ablation instrument in accordance with claim 5, wherein the first coupling member extends distally from a distal portion of the housing.
 7. The ablation instrument in accordance with claim 1, wherein the first coupling member is one of a male luer connector or a female luer connector, and the second coupling member is the other of the male luer connector or the female luer connector.
 8. The ablation instrument in accordance with claim 1, wherein the first coupling member of the handle assembly and the second coupling member of the ablation probe are configured to be detachably connected to one another via at least one of a bayonet connection, a threaded engagement, a quick disconnect, a snap fit, an interference fit, or a friction fit.
 9. An ablation instrument, comprising: a handle assembly including: a handle hypotube having a distal portion; a handle feedline extending longitudinally through the handle hypotube and configured to be coupled to an electrosurgical energy source, the handle feedline including: an outer conductor having a distal portion; and an inner conductor having a distal portion; and a handle coolant tube extending longitudinally between the handle hypotube and the outer conductor of the handle feedline to define an outflow conduit that extends longitudinally between the handle coolant tube and the handle hypotube and an inflow conduit that extends longitudinally between the handle coolant tube and the outer conductor, the handle coolant tube having a distal portion; and an ablation probe configured to detachably couple to the handle assembly, the ablation probe including: a probe hypotube having a proximal portion configured to form a fluid-tight seal with the distal portion of the handle hypotube; a probe feedline extending through the probe hypotube and including: an outer conductor having a proximal portion configured to be detachably coupled to the distal portion of the outer conductor of the handle feedline; and an inner conductor having a proximal portion configured to be detachably coupled to the distal portion of the inner conductor of the handle feedline; and a probe coolant tube extending longitudinally between the probe hypotube and the outer conductor of the probe feedline to define an outflow conduit that extends longitudinally between the probe coolant tube and the probe hypotube, and an inflow conduit that extends longitudinally between the probe coolant tube and the outer conductor of the probe feedline, the probe coolant tube having a proximal portion configured to detachably couple to the distal portion of the handle coolant tube and to selectively form a fluid-tight seal with the distal portion of the handle coolant tube such that, upon coupling of the ablation probe to the handle assembly, the inflow conduit of the probe coolant tube is continuous with the inflow conduit of the handle coolant tube and the outflow conduit of the probe coolant tube is continuous with the outflow conduit of the handle coolant tube.
 10. The ablation instrument in accordance with claim 9, wherein the handle assembly includes a first coupling member coupled to the distal portion of the handle hypotube and the ablation probe includes a second coupling member coupled to the proximal portion of the probe hypotube, the second coupling member of the ablation probe configured to be detachably coupled to the first coupling member of the handle assembly.
 11. The ablation instrument in accordance with claim 10, wherein the first coupling member is one of a male luer connector or a female luer connector, and the second coupling member is the other of the male luer connector or the female luer connector.
 12. The ablation instrument in accordance with claim 10, wherein the first coupling member of the handle assembly and the second coupling member of the ablation probe are configured to be detachably connected to one another via at least one of a bayonet connection, a threaded engagement, a quick disconnect, a snap fit, an interference fit, or a friction fit.
 13. The ablation instrument in accordance with claim 9, wherein the distal portion of the inner conductor of the handle feedline extends distally from the distal portion of the outer conductor of the handle feedline.
 14. The ablation instrument in accordance with claim 13, wherein the proximal portion of the inner conductor of the probe feedline defines an elongated cavity therein configured to detachably receive the distal portion of the inner conductor of the handle feedline.
 15. The ablation instrument in accordance with claim 9, wherein the handle assembly includes a hub having a proximal portion configured to couple to an input cable and a distal portion configured to couple to a proximal portion of the handle hypotube.
 16. The ablation instrument in accordance with claim 15, wherein the hub defines a plenum therein that is in fluid communication with the outflow conduit of the handle coolant tube, the proximal portion of the hub defining an opening in fluid communication with an outflow tube.
 17. The ablation instrument in accordance with claim 16, wherein the handle assembly includes an inflow tube coupled with a proximal portion of the inflow conduit of the handle coolant tube.
 18. The ablation instrument in accordance with claim 15, wherein the handle assembly includes a housing having the hub, the handle feedline, and the handle hypotube disposed therein. 